Hand-moving mechanism and timepiece

ABSTRACT

A hand-moving mechanism moves a hand and includes a stepping motor and a wheel train mechanism. The stepping motor includes a plurality of coils and rotates a rotational shaft thereof in forward and reverse directions. The wheel train mechanism includes a plurality of gears having: one gear which is coupled to the rotational shaft of the stepping motor; and another gear which is coupled to the hand. The stepping motor includes two coil cores which are arranged in a vicinity of a peripheral edge portion in a module having a bent peripheral edge portion, which have a linear shape respectively and which extend from a central coupling portion respectively. Each of the two coil cores is formed to be bent at a predetermined angle following a bent shape of the peripheral edge portion of the module, so as to sandwich the central coupling portion between the two coil cores.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2015-004643, filed on Jan. 14,2015, and the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The disclosure relates to a hand-moving mechanism and a timepiece havingthe same.

2. Description of the Related Art

In the related art, a retrograde mechanism that is to be used for ahand-moving mechanism of a timepiece and is configured to displaypredetermined information by reciprocally moving a hand in a fan shapehas been known. As the retrograde mechanism, a mechanical type usingcams, a spring and the like is generally used (for example, refer toJP-A-2006-170764). The mechanical retrograde mechanism is configured tosequentially move the hand from a base point by each scale by using thecams and then to rapidly swing the hand back to the base point by thesprint upon arrival of the hand at a scale end.

However, since the plurality of cams, the spring and the like arecombined in the mechanical retrograde mechanism, a structure of themechanism is very complex.

Regarding this, if the mechanical structure is simply replaced with astepping motor of a single core, it is difficult to largely changetorque that is to be applied to the hand. For this reason, it is noteasy to rapidly swing the hand having arrived at the scale end back tothe base point or to release the hand restrained due to the externalshock and the like by applying the strong torque, so that it isdifficult to favorably move the hand.

SUMMARY OF THE INVENTION

It is therefore an object of the disclosure to provide a hand-movingmechanism having a simple structure and capable of favorably moving ahand and a timepiece having the same.

According to the disclosure, a hand-moving mechanism capable offavorably moving a hand and a timepiece having the same are provided.

A hand-moving mechanism of the present invention, which is configured tomove a hand, includes a stepping motor and a wheel train mechanism. Thestepping motor includes a plurality of coils and rotates a rotationalshaft thereof in forward and reverse directions. The wheel trainmechanism includes a plurality of gears. The gears include one gearwhich is coupled to the rotational shaft of the stepping motor andanother gear which is coupled to the hand. The stepping motor includestwo coil cores. The two coil cores are arranged in a vicinity of aperipheral edge portion in a module having a bent peripheral edgeportion, have a linear shape respectively and extend from a centralcoupling portion respectively. Each of the two coil cores is formed tobe bent at a predetermined angle following a bent shape of theperipheral edge portion of the module, so as to sandwich the centralcoupling portion between the two coil cores.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a timepiece according to an illustrativeembodiment.

FIG. 2 is a plan view depicting an internal configuration of a module inthis illustrative embodiment.

FIG. 3 is a plan view of a stepping motor in this illustrativeembodiment.

FIG. 4A is a plan view of a stator main body of the stepping motor inthis illustrative embodiment, and FIG. 4B is a plan view of a coilsupport part.

FIG. 5 is a block diagram depicting a schematic control configuration ofthe timepiece according to an illustrative embodiment.

FIGS. 6A to 6C illustrate flows of a magnetic flux when rotating a rotorof the stepping motor in a forward direction.

FIGS. 7A to 7C illustrate flows of the magnetic flux when rotating therotor of the stepping motor in the forward direction.

FIGS. 8A to 8C illustrate flows of the magnetic flux when rotating therotor of the stepping motor in a reverse direction.

FIGS. 9A to 9C depict a modified embodiment when reversing the rotor ofthe stepping motor.

DESCRIPTION OF THE PREFERRED EMBODIMENT

An illustrative embodiment of the hand-moving mechanism of thedisclosure will be described with reference to FIGS. 1 to 9A to 9C.

Meanwhile, in this illustrative embodiment to be described later, avariety of definitions that are technically preferable forimplementation of the disclosure are made. However, the scope of thedisclosure is not limited to the illustrative embodiment and the shownexamples.

FIG. 1 is a plan view of a timepiece 100 according to the illustrativeembodiment.

As shown in FIG. 1, the timepiece 100 according to the illustrativeembodiment is an analog-type timepiece having a dial plate 1 and aplurality of hands 2 and configured to display time and the like bymoving the plurality of hands 2 on the circular dial plate 1.

The plurality of hands 2 includes a second hand 21, a minute hand 22 anda hour hand 23, which are configured to rotate around a substantiallycentral portion of the dial plate 1 and to display time, and two smallhands 24, 25 configured to rotate in separate small areas on the dialplate 1 and to display a variety of information.

The small hand 24 of the two small hands 24, 25 is configured to rotatein one direction, like the second hand 21, the minute hand 22 and thehour hand 23, and is used for a chronograph function, for example. Onthe other hand, the small hand 25 is a retrograde hand configured toreciprocally rotate within a fan-shaped range of a predetermined angleand to display predetermined information (a day, in this illustrativeembodiment).

The timepiece 100 has a module 3 on a backside of the dial plate 1.

FIG. 2 is a plan view depicting an internal configuration of the module3.

As shown in FIG. 2, the module 3 has a substantially circular shapecorresponding to the dial plate 1 in a plan view, and is configured toaccommodate therein a battery 36, which is a power supply unit of thetimepiece 100, a circuit substrate 37 (refer to FIG. 3) having a controlcircuit mounted thereon, a plurality of hand-moving mechanisms 4configured to move the plurality of hands 2, and the like.

The plurality of hand-moving mechanisms 4 corresponds to the pluralityof hands 2 and is configured to individually move the correspondinghands 2.

Among the plurality of hand-moving mechanisms 4, since the hand-movingmechanisms 41 to 43 corresponding to the second hand 21, the minute hand22 and the hour hand 23 are configured to move the second hand 21, theminute hand 22 and the hour hand 23 configured to rotate around thecentral portion of the dial plate 1, the hand-moving mechanisms 41 to 43are arranged to be close to a central portion in the module 3. However,in this illustrative embodiment, the hand-moving mechanism 43corresponding to the hour hand 23 is arranged at a position somewhatdistant from the central portion because of a layout space in the module3.

In the meantime, the hand-moving mechanisms 44, 45 corresponding to thetwo small hands 24, 25 are arranged in the vicinity of a curvedperipheral edge portion in the module 3 so as to avoid the hand-movingmechanisms 41 to 43, and the like.

Specifically, the plurality of hand-moving mechanisms 4 has a wheeltrain mechanism 5 and a stepping motor 6, respectively.

The wheel train mechanism 5 is configured by a plurality of gears meshedwith each other. The gear at one end is coupled to a rotational shaft ofthe stepping motor 6, and the gear at the other end is coupled to thehand 2.

The stepping motor 6 is configured to rotate the hand 2 via the wheeltrain mechanism 5.

Among the stepping motors 6 of the plurality of hand-moving mechanisms4, the stepping motors 61 to 64 corresponding to the second hand 21, theminute hand 22, the hour hand 23 and the small hand 24 have only onecoil core, respectively. Since the stepping motors 61 to 64 have ageneral structure, the detailed descriptions thereof are omitted.

On the other hand, the stepping motor 65 corresponding to the small hand25 is a dual core motor having two coil cores 86 a, 86 b, which will bedescribed later, and is configured to rotate a rotational shaft thereof(a rotor 7, which will be described later) in both forward and reversedirections. In the meantime, the stepping motor 65, the wheel trainmechanism 55 and the small hand 25 configure a retrograde mechanismconfigured to reciprocally move the small hand 25, which is a retrogradehand, within a predetermined angle range of rotation.

FIG. 3 is a plan view of the stepping motor 65.

As shown in FIG. 3, the stepping motor 65 has a rotor 7, which is arotational shaft, and a stator 8 configured to rotate the rotor 7.

The rotor 7 has a diametrically dipolar magnetized magnet attached to arotational support shaft (not shown). In this illustrative embodiment,the magnet has a disc shape, and the rotational support shaft isattached to a center of a circle of the magnet.

As the magnet configuring the rotor 7, a permanent magnet such as a rareearth magnet (for example, a samarium cobalt magnet and the like) ispreferably used. However, the type of the magnet configuring the rotor 7is not limited thereto.

The rotor 7 is accommodated in a rotor accommodation part 84 of a statormain body 80, which will be described later, and is arranged to berotatable about the rotational support shaft, which is a center ofrotation.

The rotor 7 is coupled with a predetermined gear of the wheel trainmechanism 55 (refer to FIG. 2), and the rotor 7 is rotated to rotate thegear.

The stator 8 is configured by a stator main body 80 and a coil supportpart 85.

FIG. 4A is a plan view of the stator main body 80, and FIG. 4B is a planview of the coil support part 85.

As shown in FIG. 4A, the stator main body 80 is formed of a highpermeability material such as permalloy, and has a first yoke 81, asecond yoke 82 and a third yoke 83. Also, an intersection point of thefirst yoke 81, the second yoke 82 and the third yoke 83 is formed with arotor accommodation part 84, which is a hole portion having asubstantially circular shape. In the rotor accommodation part 84, therotor 7 is arranged to be rotatable.

Also, each of the second yoke 82 and the third yoke 83 is somewhat bentso as to sandwich the rotor accommodation part 84 between the secondyoke 82 and the third yoke 83 so that an angle therebetween at anopposite side to the first yoke 81 is less than 180°.

An inner periphery of the rotor accommodation part 84 is provided withthree recess portions 84 a. The three recess portions 84 a are astator-side stationary portion for keeping a stationary state of therotor 7, and are provided to magnetically stabilize and stop the rotor 7at a predetermined position at a non-energization state of the steppingmotor 65.

The first yoke 81, the second yoke 82 and the third yoke 83 arerespectively provided at free ends thereof with coupling holes 81 a, 82a, 83 a for coupling the stator main body 80 to the coil support part85.

As shown in FIG. 4B, the coil support part 85 is formed of a highpermeability material such as permalloy, and has a shape where two coilcores 86 a, 86 b are coupled with a central coupling portion 87.

The two coil cores 86 a, 86 b are configured to carry coils 88 (a firstcoil 88 a and a second coil 88 b) wound onto the coil cores 86 a, 86 b.In this way, the coils 88 are respectively carried on the two coil cores86 a, 86 b, so that two coil blocks 89 (a first coil block 89 a and asecond coil block 89 b) are configured. Meanwhile, in this illustrativeembodiment, the two coil cores 86 a, 86 b have substantially the samelength, and amounts of the coils 88 to be wound (the number of turns)are also substantially the same.

Also, the two coil cores 86 a, 86 b are substantially linear but arebent with each other at a predetermined angle about the coupling portion87 so as to follow a curved shape of the peripheral edge portion of themodule 3 (refer to FIG. 3). That is each of the two coil cores 86 a, 86b is formed to be bent at a predetermined angle following a bent shapeof the peripheral edge portion of the module 3 so as to sandwich thecoupling portion 87 between the two coil cores 86 a, 86 b.

The coupling portion 87 of the coil support part 85 and both endsthereof are provided with three coupling holes 85 a to 85 c for couplingthe coil support part 85 to the stator main body 80. The three couplingholes 85 a to 85 c are screw-fastened to the coupling holes 81 a, 82 a,83 a of the stator main body 80, respectively, so that the stator mainbody 80 and the coil support part 85 are magnetically connected.

As shown in FIG. 3, the two coil blocks 89 of the coil support part 85are arranged to magnetically connect the first yoke 81, the second yoke82 and the third yoke 83 of the stator main body 80 at a state where thestator main body 80 and the coil support part 85 are fixed.

Specifically, the first coil block 89 a is arranged to magneticallyconnect the first yoke 81 and the second yoke 82, and the second coilblock 89 b is arranged to magnetically connect the first yoke 81 and thethird yoke 83.

Both ends of the coil support part 85 are provided with two coilsubstrates 91. Each coil substrate 91 is mounted with two coil terminals92, and the two coil terminals 92 are connected with both ends of thecoils 88 positioned at sides close to the coil substrates 91.

Peripheries of the two coil terminals 92 of each coil substrate 91 arecovered with a protective resin 93 for preventing breaking of the coil,together with an end portion of the connected coil 88. For this reason,a covering portion of the protective resin 93 is convex to be higherthan a surface of the coil substrate 91.

Also, the two coil substrates 91 are electrically connected to thecircuit substrate 37 arranged above the two coil substrates.

The circuit substrate 37 is formed with two notches 37 a for avoidingthe two protective resins 93 more convex than the surfaces of the coilsubstrates 91 so that the notches open towards an outer periphery of themodule 3. For this reason, the circuit substrate 37 is securelysurface-contacted to the two coil substrates 91 while avoiding overlapswith the two protective resins 93.

FIG. 5 is a block diagram depicting a schematic control configuration ofthe timepiece 100.

As shown in FIG. 5, the timepiece 100 has a control unit 38 (a motordriving control unit). The control unit 38 is configured by a CPU(Central Processing Unit) and the like mounted on the circuit substrate37, and is configured to collectively control respective units of thetimepiece 100.

Specifically, the control unit 38 is configured to apply driving pulsesto the stepping motors 6 of the plurality of hand-moving mechanisms 4 byusing the battery 36 as a power supply unit, thereby controlling thedriving of the stepping motors 6 and the rotation driving of the hands2.

In particular, the control unit 38 is configured to control rotation ofthe rotor 7 of the stepping motor 65 and the small hand 25 (theretrograde hand) with a predetermined step angle in any direction of aforward rotation direction (a clockwise direction) and a reversedirection (a counterclockwise direction) by individually controllingenergization (applying of the driving pulse) to the two coils 88 of thestepping motor 65, which is a dual core motor.

Subsequently, an operating aspect of the retrograde mechanism of thetimepiece 100 is described.

First, a display hand-moving operation of rotating the small hand 25(the retrograde hand) in the forward rotation direction (the clockwisedirection) to display predetermined information (day, in thisillustrative embodiment) with the small hand 25 is described withreference to FIGS. 6A to 6C and 7A to 7C.

FIGS. 6A to 6C and 7A to 7C illustrate flows of a magnetic flux whenrotating the rotor 7 of the stepping motor 65 in the forward directionin a case where the number of coils to be energized at the same time isone.

In this illustrative embodiment, when no coils 88 are energized, therotor 7 is stationary at a state where a magnetic pole of the first yoke81 opposing to an S-pole of the rotor 7 is an N-pole and the two recessportions 84 a of the second yoke 82-side and the third yoke 83-side anda polarization position of the magnet of the rotor 7 face each other,for example.

When rotating the rotor 7 from the state in the forward direction, thecontrol unit 38 first applies a driving pulse of a positive directiononly to the second coil 88 b. Thereby, as shown in FIG. 6A, a magneticflux of a direction shown with the solid line is generated in the secondcoil 88 b, the magnetic pole of the first yoke 81 becomes the N-pole andthe magnetic pole of the third yoke 83 becomes the S-pole. Further, themagnetic flux flows to the second yoke 82 through the first yoke 81 andthe coil core 86 a of the first coil 88 a, so that the magnetic pole ofthe second yoke 82 becomes the N-pole. As a result, the rotor 7 startsto rotate in the forward rotation direction while the N-pole thereof isbeing attracted to the third yoke 83 of the S-pole.

Then, the control unit 38 applies the driving pulse of the positivedirection only to the first coil 88 a. At this time, the control unit 38sets an applying time period of the driving pulse to be long (forexample, 50% or greater and less than 100% of an entire applying timeperiod upon rotation of the rotor by 180°) so as to largely rotate therotor 7. Thereby, as shown in FIG. 6B, a magnetic flux of a directionshown with the solid line is generated in the first coil 88 a, themagnetic pole of the first yoke 81 becomes the S-pole and the magneticpole of the second yoke 82 becomes the N-pole. Further, the magneticflux flows to the third yoke 83 through the first yoke 81 and the coilcore 86 b of the second coil 88 b, so that the magnetic pole of thethird yoke 83 becomes the S-pole. As a result, the rotor 7 furtherrotates in the forward rotation direction while the S-pole thereof isbeing attracted to the second yoke 82 of the N-pole.

Then, the control unit 38 applies a driving pulse of a negativedirection only to the second coil 88 b. Thereby, as shown in FIG. 6C, amagnetic flux of a direction shown with the solid line is generated inthe second coil 88 b, the magnetic pole of the first yoke 81 becomes theS-pole and the magnetic pole of the third yoke 83 becomes the N-pole.Further, the magnetic flux flows to the second yoke 82 through the firstyoke 81 and the coil core 86 a of the first coil 88 a, so that themagnetic pole of the second yoke 82 becomes the S-pole. As a result, therotor 7 rotates in the forward rotation direction while the N-polethereof is being repulsive to the third yoke 83 of the N-pole, and isstationary at a magnetically stable position at which the two recessportions 84 a of the second yoke 82-side and the third yoke 83-side andthe polarization position of the magnet of the rotor 7 face each other,i.e., at a position rotated from the rotation start position by 180°(hereinafter, referred to as ‘half rotation position’).

As the rotor 7 of the stepping motor 65 is rotated from the rotationstart position by 180°, the small hand 25 is rotated forward by apredetermined step angle by the wheel train mechanism 55 configured tocouple the rotor 7 and the small hand 25 in a predetermined gear ratio.Thereby, in this illustrative embodiment, a day indicated by the smallhand 25 is changed to a next day (refer to FIG. 1).

When further rotating the rotor 7 from the half rotation position in theforward direction by 180° to return the same to the rotation startposition, the control unit 38 applies the driving pulse of the negativedirection only to the second coil 88 b. Thereby, as shown in FIG. 7A, amagnetic flux of a direction shown with the solid line is generated inthe second coil 88 b, the magnetic pole of the first yoke 81 becomes theS-pole and the magnetic pole of the third yoke 83 becomes the N-pole.Further, the magnetic flux flows to the second yoke 82 through the firstyoke 81 and the coil core 86 a of the first coil 88 a, so that themagnetic pole of the second yoke 82 becomes the S-pole. As a result, therotor 7 rotates in the forward rotation direction while the S-polethereof is being attracted to the magnetic pole of the third yoke 83 ofthe N-pole.

Then, the control unit 38 applies the driving pulse of the positivedirection only to the first coil 88 a. At this time, the control unit 38sets an applying time period of the driving pulse to be long (forexample, 50% or greater and less than 100% of the entire applying timeperiod upon rotation of the rotor by 180°) so as to largely rotate therotor 7. Thereby, as shown in FIG. 7B, a magnetic flux of a directionshown with the solid line is generated in the first coil 88 a, themagnetic pole of the first yoke 81 becomes the N-pole and the magneticpole of the second yoke 82 becomes the S-pole. Further, the magneticflux flows to the third yoke 83 through the first yoke 81 and the coilcore 86 b of the second coil 88 b, so that the magnetic pole of thethird yoke 83 becomes the N-pole. As a result, the rotor 7 furtherrotates in the forward rotation direction while the N-pole thereof isbeing attracted to the second yoke 82 of the S-pole.

Then, the control unit 38 applies the driving pulse of the positivedirection only to the second coil 88 b. Thereby, as shown in FIG. 7C, amagnetic flux of a direction shown with the solid line is generated inthe second coil 88 b, the magnetic pole of the first yoke 81 becomes theN-pole and the magnetic pole of the third yoke 83 becomes the S-pole.Further, the magnetic flux flows to the second yoke 82 through the firstyoke 81 and the coil core 86 a of the first coil 88 a, so that themagnetic pole of the second yoke 82 becomes the N-pole. As a result, therotor 7 is stationary at the magnetically stable position at which thetwo recess portions 84 a of the second yoke 82-side and the third yoke83-side and the polarization position of the magnet of the rotor 7 faceeach other, i.e., at a position further rotated from the half rotationposition by 180° while the S-pole thereof is being repulsive to thethird yoke 83 of the S-pole.

As the rotor 7 of the stepping motor 65 is rotated from the halfrotation position by 180°, the small hand 25 is rotated forward by thepredetermined step angle by the wheel train mechanism 55 configured tocouple the rotor 7 and the small hand 25 in the predetermined gearratio. Thereby, in this illustrative embodiment, a day indicated by thesmall hand 25 is further changed to a next day (refer to FIG. 1).

In this way, according to this illustrative embodiment, during thedisplay hand-moving operation of the small hand 25, only one of the twocoils 88 is energized to rotate the small hand 25 (i.e., the rotor 7).

Subsequently, a non-display hand-moving operation of swinging the smallhand 25 back to a base point (left end) of the rotation range withoutdisplaying the information by energizing both the two coils 88 torapidly rotate the small hand 25 in the reverse rotation direction (thecounterclockwise direction) is described with reference to FIGS. 8A to8C.

FIGS. 8A to 8C illustrate flows of the magnetic flux when reversing therotor 7 of the stepping motor 65.

In this illustrative embodiment, when no coils 88 are energized, therotor 7 is stationary at a state where the magnetic pole of the firstyoke 81 opposing to the N-pole of the rotor 7 becomes the S-pole and thetwo recess portions 84 a of the second yoke 82-side and the third yoke83-side and the polarization position of the magnet of the rotor 7 faceeach other, for example.

When rapidly reversing the rotor 7 from the state, the control unit 38first applies the driving pulse of the positive direction to the firstcoil 88 a, and at the same time, applies the driving pulse of thepositive direction to the second coil 88 b. Thereby, as shown in FIG.8A, magnetic fluxes shown with the solid lines are generated in thefirst coil 88 a and the second coil 88 b, the magnetic pole of thesecond yoke 82 becomes the N-pole, and the magnetic pole of the thirdyoke 83 becomes the S-pole. As a result, the rotor 7 starts to rotate inthe reverse rotation direction while the S-pole thereof is beingattracted to the second yoke 82 of the N-pole.

Then, the control unit 38 applies the driving pulse of the negativedirection to the first coil 88 a, and at the same time, applies thedriving pulse of the positive direction to the second coil 88 b.Thereby, as shown in FIG. 8B, magnetic fluxes shown with the solid linesare generated in the first coil 88 a and the second coil 88 b, themagnetic pole of the first yoke 81 becomes the N-pole, and the magneticpoles of the second yoke 82 and the third yoke 83 become the S-pole. Asa result, the rotor 7 further rotates in the reverse rotation directionwhile the S-pole thereof is being attracted to the first yoke 81 of theN-pole.

Then, as shown in FIG. 8C, the rotor 7 is stationary at the magneticallystable position at which the two recess portions 84 a of the second yoke82-side and the third yoke 83-side and the polarization position of themagnet of the rotor 7 face each other, i.e., at the position furtherrotated from the half rotation position by 180°.

Thereafter, while the control unit 38 energizes the two coils 88 at thesame time, the control unit sequentially changes the magnetic poles ofthe respective yokes 81 to 83 as the rotor 7 rotates, therebycontinuously rotating the rotor 7 in the reverse rotation direction.Then, the control unit 38 rotates the rotor 7 until the small hand 25reaches the left end of the rotation range, and then stops the rotor 7.

In this way, according to this illustrative embodiment, during thenon-display hand-moving operation of the small hand 25, the small hand25 (i.e., the rotor 7) is rotated by energizing the two coils 88 at thesame time. For this reason, it is possible to swing the small hand 25back in a much shorter time, as compared to the display hand-movingoperation.

In the meantime, the ‘non-display hand-moving operation’ of energizingthe two coils 88 at the same time is not limited to the configurationwhere the corresponding operation is performed when swinging the smallhand 25 back. For example, the ‘non-display hand-moving operation’ maybe performed when the information display by the small hand 25 is notaccompanied, for example when it is intended to release the small hand25 restrained due to an external shock and the like, when making abacklash, and the like.

As described above, according to this illustrative embodiment, thenumber of the coils 88 of the stepping motor 65 to be energized at thesame time is different upon the display hand-moving operation where thesmall hand 25 displays the predetermined information and upon thenon-display hand-moving operation where the small hand 25 does notdisplay the predetermined information.

For this reason, it is possible to favorably move the small hand 25 byswinging the small hand 25 back at a rapid speed at which a viewercannot recognize the same or by applying high torque to the restrainedsmall hand 25 to release the restraint.

Also, it is possible to rotate the rotor 7 with high torque in anydirection of the forward and reverse directions just by increasing thenumber of the coils 88 to be energized.

For this reason, it is possible to favorably move the small hand 25 witha simpler structure, as compared to the mechanical structure where aplurality of cams, a spring and the like are combined.

Also, according to the stepping motor 65, the two coil cores 86 a, 86 barranged in the vicinity of the peripheral edge portion of the module 3and extending from the central coupling portion 87 are bent with eachother about the central coupling portion 87 at the predetermined anglefollowing the curved shape of the peripheral edge portion of the module3.

For this reason, it is possible to arrange the two coil cores 86 a, 86b, and further the two coil blocks 89 in the vicinity of the peripheraledge portion so that they follow the peripheral edge portion of themodule 3. Therefore, it is possible to easily implement the arrangementlayout in the module 3 where the hand-moving mechanisms 41 to 43corresponding to the second hand 21, the minute hand 22 and the hourhand 23 are arranged in the vicinity of the central portion in themodule 3.

At this time, if the two coil cores 86 a, 86 b are bent to follow theperipheral edge portion of the module 3, the coils 88 are wound withbeing biased toward the coil cores 86 a, 86 b, so that the number ofturns is resultantly reduced. In this illustrative embodiment, since thetwo coil cores 86 a, 86 b are linearly formed and are also bent witheach other, it is possible to arrange the two coil blocks 89 in thevicinity of the peripheral edge portion in the module 3 without causingthe decrease in the number of turns.

Also, the stepping motor 65 has the coil substrates 91, to which bothends of the coils 88 wound onto the respective coil cores 86 a, 86 b areconnected, at the sides closer to the respective tips than the two coilcores 86 a, 86 b arranged in the vicinity of the peripheral edge portionin the module 3 and extending from the central coupling portion 87. Inthe stepping motor 65, the parts of the coil substrates 91, to whichboth ends of the coils 88 are connected, are covered with the protectiveresins 93, and the circuit substrate 37 having the notches 37 a formed,which open towards the outer periphery of the module 3 while avoidingthe protective resins, and the coil substrate 91 are surface-contactedeach other.

That is, the coil substrates 91 are provided at both ends of the twocoil cores 86 a, 86 b, so that it is possible to favorablysurface-contact the coil substrates 91 and the circuit substrate 37while avoiding the protective resins 93 by the notches 37 a openingtoward the outer periphery of the module 3.

In contrast, if the coil substrate 91 is provided at the couplingportion 87 between the two coil cores 86 a, 86 b, the coil substrate 91on the coupling portion 87 is covered with the protective resin 93. Inthis case, since it is necessary to enable a wiring pattern to pass apart of the circuit substrate 37 connected to the coil substrate 91, ashape for avoiding the protective resin 93 is not the notch formedtoward the outer periphery but is a hole portion in which a wiringpattern part of the circuit substrate 37 exists at the outerperiphery-side. Further, a part of the circuit substrate 37 positionedat an outermore periphery than the hole portion is necessarily formed tohave a predetermined width or greater from a standpoint of the shockresistance. That is, since the circuit substrate 37 protrudes towardsthe outer periphery by a distance corresponding to the width, thestepping motor 65 should be arranged at an inner periphery-side of themodule 3 so as to avoid the interference between the circuit substrate37 and the module 3.

Therefore, in this illustrative embodiment, the coil substrates 91 areprovided at both ends of the two coil cores 86 a, 86 b, so that it ispossible to arrange the stepping motor 65 in the vicinity of theperipheral edge portion of the module 3 and to easily implement thearrangement layout in the module 3, differently from the configurationwhere the coil substrate 91 is provided between the two coil cores 86 a,86 b.

In the above illustrative embodiment, the non-display hand-movingoperation where both the two coils 88 are energized to rapidly rotatethe small hand 25 in the reverse direction (the counterclockwisedirection) and to thus swing the small hand 25 back to the base point(left end) of the rotation range without displaying the information hasbeen described. However, as shown in FIGS. 9A to 9C, the number of thecoils 88 to be energized may be a combination of two and one. Also inthis configuration, it is possible to swing the small hand 25 back in amuch shorter time, as compared to the display hand-moving operationwhere the number of the coils to be energized at the same time is one.

The illustrative embodiment to which the disclosure can be applied isnot limited to the above illustrative embodiment, and can be variouslychanged without departing from the gist of the disclosure.

For example, in the above illustrative embodiment, the small hand 25 isconfigured to rotate in the forward rotation direction upon the displayhand-moving operation and to rotate in the reverse rotation directionupon the non-display hand-moving operation. However, the relationbetween the rotation direction of the small hand 25 and the displayaspect is not particularly limited, and the rotation direction may beassociated with a type of the information that is to be displayed by thesmall hand 25, too. Accordingly, for example, the display hand-movingoperation of displaying the information upon the rotation of the smallhand 25 in both the forward and reverse directions may also beperformed.

Also, in the above illustrative embodiment, when the rotor 7 of thestepping motor 65 is rotated in the forward rotation direction, thesmall hand 25 is also rotated in the forward rotation direction.However, the relation between the rotation directions of the rotor 7 andthe small hand 25 is not particularly limited inasmuch as theycorrespond to each other.

Also, in the above illustrative embodiment, the stepping motor 65 hasthe two coils 88. However, the number of the coils 88 is notparticularly limited inasmuch as a plurality of the coils 88 isprovided. For example, the number of the coils 88 may be three or more.

Also, in the above illustrative embodiment, the retrograde mechanismincluding the small hand 25 (the retrograde hand), the wheel trainmechanism 55 and the stepping motor 65 is provided for the analog-typetimepiece 100. However, the timepiece is not limited to the analog type.

The retrograde mechanism may be provided for a digital-type timepiecehaving a dial plate (for example, a liquid crystal display unit, and thelike) configured to display a variety of information such as time andcalendar information by characters and the like or may be provided for atimepiece having two analog-type and digital-type display units.

Although the illustrative embodiments of the disclosure have beendescribed, the scope of the disclosure is not limited to theillustrative embodiments and the disclosure includes the scope definedin the claims and the equivalent scope thereto.

What is claimed is:
 1. A hand-moving mechanism configured to move ahand, the hand-moving mechanism comprising: a stepping motor thatincludes a plurality of coils and that rotates a rotational shaftthereof in forward and reverse directions; and a wheel train mechanismthat includes a plurality of gears comprising: one gear which is coupledto the rotational shaft of the stepping motor; and another gear which iscoupled to the hand, wherein the stepping motor includes two coil coreswhich are arranged in a vicinity of a peripheral edge portion in amodule having a bent peripheral edge portion, each of the two coil coreshaving a linear shape and extending from a central coupling portion,wherein each of the two coil cores is formed to be bent at apredetermined angle following a bent shape of the peripheral edgeportion of the module, so as to sandwich the central coupling portionbetween the two coil cores, wherein the hand-moving mechanism furthercomprises coil substrates that are arranged at sides closer torespective end portions than the two coil cores, wherein both ends ofcoils wound onto the respective coil cores are connected to the coilsubstrates, wherein portions where both ends of the coils are connectedto the coil substrates are covered with protective resins, wherein thecoil substrates and a circuit substrate have a surface contact with eachother, wherein the circuit substrate includes notches which open towardsan outer periphery of the module while avoiding an overlap with theprotective resins, and wherein the protective resins are provided onlyat portions where the notches are formed on the circuit substrate. 2.The hand-moving mechanism according to claim 1, further comprising: amotor driving control unit that individually controls energization toeach coil to drive the stepping motor, wherein a number of the coils tobe simultaneously energized in a display hand-moving operation isdifferent from a number of the coils to be simultaneously energized in anon-display hand-moving operation.
 3. The hand-moving mechanismaccording to claim 2, wherein the stepping motor has two coils, whereinthe motor driving control unit energizes only one coil to rotate thehand in one direction in the display hand-moving operation, and whereinthe motor driving control unit energizes the two coils to rotate thehand in the other direction in the non-display hand-moving operation. 4.A timepiece comprising the hand-moving mechanism according to claim 3.5. A timepiece comprising the hand-moving mechanism according to claim2.
 6. The hand-moving mechanism according to claim 1, furthercomprising: a motor driving control unit that individually controlsenergization to each coil to drive the stepping motor, wherein thestepping motor has two coils, wherein the motor driving control unitenergizes only one coil to rotate the hand in one direction in a displayhand-moving operation, and wherein the motor driving control unitenergizes the two coils to rotate the hand in the other direction in anon-display hand-moving operation.
 7. A timepiece comprising thehand-moving mechanism according to claim
 6. 8. A timepiece comprisingthe hand-moving mechanism according to claim 1.